// Copyright: Hiroshi Ichikawa <http://gimite.net/en/>
// License: New BSD License
// Reference: http://dev.w3.org/html5/websockets/
// Reference: http://tools.ietf.org/html/rfc6455

(function () {

	if (window.WEB_SOCKET_FORCE_FLASH) {
		// Keeps going.
	} else if (window.WebSocket) {
		return;
	} else if (window.MozWebSocket) {
		// Firefox.
		window.WebSocket = MozWebSocket;
		return;
	}

	var logger;
	if (window.WEB_SOCKET_LOGGER) {
		logger = WEB_SOCKET_LOGGER;
	} else if (window.console && window.console.log && window.console.error) {
		// In some environment, console is defined but console.log or console.error is missing.
		logger = window.console;
	} else {
		logger = {log: function () {
			}, error: function () {
			}};
	}

	// swfobject.hasFlashPlayerVersion("10.0.0") doesn't work with Gnash.
	if (swfobject.getFlashPlayerVersion().major < 10) {
		logger.error("Flash Player >= 10.0.0 is required.");
		return;
	}
	if (location.protocol == "file:") {
		logger.error(
			"WARNING: web-socket-js doesn't work in file:///... URL " +
			"unless you set Flash Security Settings properly. " +
			"Open the page via Web server i.e. http://...");
	}

	/**
	 * Our own implementation of WebSocket class using Flash.
	 * @param {string} url
	 * @param {array or string} protocols
	 * @param {string} proxyHost
	 * @param {int} proxyPort
	 * @param {string} headers
	 */
	window.WebSocket = function (url, protocols, proxyHost, proxyPort, headers) {
		var self = this;
		self.__id = WebSocket.__nextId++;
		WebSocket.__instances[self.__id] = self;
		self.readyState = WebSocket.CONNECTING;
		self.bufferedAmount = 0;
		self.__events = {};
		if (!protocols) {
			protocols = [];
		} else if (typeof protocols == "string") {
			protocols = [protocols];
		}
		// Uses setTimeout() to make sure __createFlash() runs after the caller sets ws.onopen etc.
		// Otherwise, when onopen fires immediately, onopen is called before it is set.
		self.__createTask = setTimeout(function () {
			WebSocket.__addTask(function () {
				self.__createTask = null;
				WebSocket.__flash.create(
					self.__id, url, protocols, proxyHost || null, proxyPort || 0, headers || null);
			});
		}, 0);
	};

	/**
	 * Send data to the web socket.
	 * @param {string} data  The data to send to the socket.
	 * @return {boolean}  True for success, false for failure.
	 */
	WebSocket.prototype.send = function (data) {
		if (this.readyState == WebSocket.CONNECTING) {
			throw "INVALID_STATE_ERR: Web Socket connection has not been established";
		}
		// We use encodeURIComponent() here, because FABridge doesn't work if
		// the argument includes some characters. We don't use escape() here
		// because of this:
		// https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Functions#escape_and_unescape_Functions
		// But it looks decodeURIComponent(encodeURIComponent(s)) doesn't
		// preserve all Unicode characters either e.g. "\uffff" in Firefox.
		// Note by wtritch: Hopefully this will not be necessary using ExternalInterface.  Will require
		// additional testing.
		var result = WebSocket.__flash.send(this.__id, encodeURIComponent(data));
		if (result < 0) { // success
			return true;
		} else {
			this.bufferedAmount += result;
			return false;
		}
	};

	/**
	 * Close this web socket gracefully.
	 */
	WebSocket.prototype.close = function () {
		if (this.__createTask) {
			clearTimeout(this.__createTask);
			this.__createTask = null;
			this.readyState = WebSocket.CLOSED;
			return;
		}
		if (this.readyState == WebSocket.CLOSED || this.readyState == WebSocket.CLOSING) {
			return;
		}
		this.readyState = WebSocket.CLOSING;
		WebSocket.__flash.close(this.__id);
	};

	/**
	 * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
	 *
	 * @param {string} type
	 * @param {function} listener
	 * @param {boolean} useCapture
	 * @return void
	 */
	WebSocket.prototype.addEventListener = function (type, listener, useCapture) {
		if (!(type in this.__events)) {
			this.__events[type] = [];
		}
		this.__events[type].push(listener);
	};

	/**
	 * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
	 *
	 * @param {string} type
	 * @param {function} listener
	 * @param {boolean} useCapture
	 * @return void
	 */
	WebSocket.prototype.removeEventListener = function (type, listener, useCapture) {
		if (!(type in this.__events))
			return;
		var events = this.__events[type];
		for (var i = events.length - 1; i >= 0; --i) {
			if (events[i] === listener) {
				events.splice(i, 1);
				break;
			}
		}
	};

	/**
	 * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
	 *
	 * @param {Event} event
	 * @return void
	 */
	WebSocket.prototype.dispatchEvent = function (event) {
		var events = this.__events[event.type] || [];
		for (var i = 0; i < events.length; ++i) {
			events[i](event);
		}
		var handler = this["on" + event.type];
		if (handler)
			handler.apply(this, [event]);
	};

	/**
	 * Handles an event from Flash.
	 * @param {Object} flashEvent
	 */
	WebSocket.prototype.__handleEvent = function (flashEvent) {

		if ("readyState" in flashEvent) {
			this.readyState = flashEvent.readyState;
		}
		if ("protocol" in flashEvent) {
			this.protocol = flashEvent.protocol;
		}

		var jsEvent;
		if (flashEvent.type == "open" || flashEvent.type == "error") {
			jsEvent = this.__createSimpleEvent(flashEvent.type);
		} else if (flashEvent.type == "close") {
			jsEvent = this.__createSimpleEvent("close");
			jsEvent.wasClean = flashEvent.wasClean ? true : false;
			jsEvent.code = flashEvent.code;
			jsEvent.reason = flashEvent.reason;
		} else if (flashEvent.type == "message") {
			var data = decodeURIComponent(flashEvent.message);
			jsEvent = this.__createMessageEvent("message", data);
		} else {
			throw "unknown event type: " + flashEvent.type;
		}

		this.dispatchEvent(jsEvent);

	};

	WebSocket.prototype.__createSimpleEvent = function (type) {
		if (document.createEvent && window.Event) {
			var event = document.createEvent("Event");
			event.initEvent(type, false, false);
			return event;
		} else {
			return {type: type, bubbles: false, cancelable: false};
		}
	};

	WebSocket.prototype.__createMessageEvent = function (type, data) {
		if (window.MessageEvent && typeof (MessageEvent) == "function" && !window.opera) {
			return new MessageEvent("message", {
				"view": window,
				"bubbles": false,
				"cancelable": false,
				"data": data
			});
		} else if (document.createEvent && window.MessageEvent && !window.opera) {
			var event = document.createEvent("MessageEvent");
			event.initMessageEvent("message", false, false, data, null, null, window, null);
			return event;
		} else {
			// Old IE and Opera, the latter one truncates the data parameter after any 0x00 bytes.
			return {type: type, data: data, bubbles: false, cancelable: false};
		}
	};

	/**
	 * Define the WebSocket readyState enumeration.
	 */
	WebSocket.CONNECTING = 0;
	WebSocket.OPEN = 1;
	WebSocket.CLOSING = 2;
	WebSocket.CLOSED = 3;

	// Field to check implementation of WebSocket.
	WebSocket.__isFlashImplementation = true;
	WebSocket.__initialized = false;
	WebSocket.__flash = null;
	WebSocket.__instances = {};
	WebSocket.__tasks = [];
	WebSocket.__nextId = 0;

	/**
	 * Load a new flash security policy file.
	 * @param {string} url
	 */
	WebSocket.loadFlashPolicyFile = function (url) {
		WebSocket.__addTask(function () {
			WebSocket.__flash.loadManualPolicyFile(url);
		});
	};

	/**
	 * Loads WebSocketMain.swf and creates WebSocketMain object in Flash.
	 */
	WebSocket.__initialize = function () {

		if (WebSocket.__initialized)
			return;
		WebSocket.__initialized = true;

		if (WebSocket.__swfLocation) {
			// For backword compatibility.
			window.WEB_SOCKET_SWF_LOCATION = WebSocket.__swfLocation;
		}
		if (!window.WEB_SOCKET_SWF_LOCATION) {
			logger.error("[WebSocket] set WEB_SOCKET_SWF_LOCATION to location of WebSocketMain.swf");
			return;
		}
		if (!window.WEB_SOCKET_SUPPRESS_CROSS_DOMAIN_SWF_ERROR &&
			!WEB_SOCKET_SWF_LOCATION.match(/(^|\/)WebSocketMainInsecure\.swf(\?.*)?$/) &&
			WEB_SOCKET_SWF_LOCATION.match(/^\w+:\/\/([^\/]+)/)) {
			var swfHost = RegExp.$1;
			if (location.host != swfHost) {
				logger.error(
					"[WebSocket] You must host HTML and WebSocketMain.swf in the same host " +
					"('" + location.host + "' != '" + swfHost + "'). " +
					"See also 'How to host HTML file and SWF file in different domains' section " +
					"in README.md. If you use WebSocketMainInsecure.swf, you can suppress this message " +
					"by WEB_SOCKET_SUPPRESS_CROSS_DOMAIN_SWF_ERROR = true;");
			}
		}
		var container = document.createElement("div");
		container.id = "webSocketContainer";
		// Hides Flash box. We cannot use display: none or visibility: hidden because it prevents
		// Flash from loading at least in IE. So we move it out of the screen at (-100, -100).
		// But this even doesn't work with Flash Lite (e.g. in Droid Incredible). So with Flash
		// Lite, we put it at (0, 0). This shows 1x1 box visible at left-top corner but this is
		// the best we can do as far as we know now.
		container.style.position = "absolute";
		if (WebSocket.__isFlashLite()) {
			container.style.left = "0px";
			container.style.top = "0px";
		} else {
			container.style.left = "-100px";
			container.style.top = "-100px";
		}
		var holder = document.createElement("div");
		holder.id = "webSocketFlash";
		container.appendChild(holder);
		document.body.appendChild(container);
		// See this article for hasPriority:
		// http://help.adobe.com/en_US/as3/mobile/WS4bebcd66a74275c36cfb8137124318eebc6-7ffd.html
		swfobject.embedSWF(
			WEB_SOCKET_SWF_LOCATION,
			"webSocketFlash",
			"1" /* width */,
			"1" /* height */,
			"10.0.0" /* SWF version */,
			null,
			null,
			{hasPriority: true, swliveconnect: true, allowScriptAccess: "always"},
		null,
			function (e) {
				if (!e.success) {
					logger.error("[WebSocket] swfobject.embedSWF failed");
				}
			}
		);

	};

	/**
	 * Called by Flash to notify JS that it's fully loaded and ready
	 * for communication.
	 */
	WebSocket.__onFlashInitialized = function () {
		// We need to set a timeout here to avoid round-trip calls
		// to flash during the initialization process.
		setTimeout(function () {
			WebSocket.__flash = document.getElementById("webSocketFlash");
			WebSocket.__flash.setCallerUrl(location.href);
			WebSocket.__flash.setDebug(!!window.WEB_SOCKET_DEBUG);
			for (var i = 0; i < WebSocket.__tasks.length; ++i) {
				WebSocket.__tasks[i]();
			}
			WebSocket.__tasks = [];
		}, 0);
	};

	/**
	 * Called by Flash to notify WebSockets events are fired.
	 */
	WebSocket.__onFlashEvent = function () {
		setTimeout(function () {
			try {
				// Gets events using receiveEvents() instead of getting it from event object
				// of Flash event. This is to make sure to keep message order.
				// It seems sometimes Flash events don't arrive in the same order as they are sent.
				var events = WebSocket.__flash.receiveEvents();
				for (var i = 0; i < events.length; ++i) {
					WebSocket.__instances[events[i].webSocketId].__handleEvent(events[i]);
				}
			} catch (e) {
				logger.error(e);
			}
		}, 0);
		return true;
	};

	// Called by Flash.
	WebSocket.__log = function (message) {
		logger.log(decodeURIComponent(message));
	};

	// Called by Flash.
	WebSocket.__error = function (message) {
		logger.error(decodeURIComponent(message));
	};

	WebSocket.__addTask = function (task) {
		if (WebSocket.__flash) {
			task();
		} else {
			WebSocket.__tasks.push(task);
		}
	};

	/**
	 * Test if the browser is running flash lite.
	 * @return {boolean} True if flash lite is running, false otherwise.
	 */
	WebSocket.__isFlashLite = function () {
		if (!window.navigator || !window.navigator.mimeTypes) {
			return false;
		}
		var mimeType = window.navigator.mimeTypes["application/x-shockwave-flash"];
		if (!mimeType || !mimeType.enabledPlugin || !mimeType.enabledPlugin.filename) {
			return false;
		}
		return mimeType.enabledPlugin.filename.match(/flashlite/i) ? true : false;
	};

	if (!window.WEB_SOCKET_DISABLE_AUTO_INITIALIZATION) {
		// NOTE:
		//   This fires immediately if web_socket.js is dynamically loaded after
		//   the document is loaded.
		swfobject.addDomLoadEvent(function () {
			WebSocket.__initialize();
		});
	}

})();
